Remediation of trichloroethylene in an artificial aquifer with trees: A controlled field study

Poplar trees have been evaluated in the field for the control of contaminated groundwater movement, but to date, the fate of the contaminants has not been demonstrated. In the present study, we tested a hybrid poplar for the uptake and degradation of trichloroethylene (TCE). Plants were exposed to TCE-contaminated groundwater under field conditions in lined cells for three years. During the growing seasons, the trees were able to remove over 99% of the added TCE. Less than 9% of the TCE was transpired to the atmosphere during the second and third years, and examination of the tissue showed expected metabolites, but at low levels. Chloride did not significantly accumulate in the plant tissues, but chloride ion increased in the soil in amounts that approximately corresponded to TCE loss. These results demonstrate that treatment of TCE-contaminated groundwater with this poplar clone can result in efficient destruction of TCE.